Drying plant.



w.1. KENNY.

DRYING PLANT.

APPLICATION FILED MAR. 2. 1912.

1,l72,291 Patented Feb.22,1916.

2 SHEETS-SHEET l.

W. J. KENNEY.

DRYING PLANT.

APPLlcATmN FILED MAR.2.1912.

2 SHEETS-SHEET 2.

Patented Feb. 22, 1916.

" ,narran sTiaTns PATENT @Triton WILLIAM J. KENNEY, OF WILMIET'IE,ILLINOIS, ASSIGNOR TO UNDERFEED STOKER COMIANY OF AMERICA, OF CHICAGO,ILLINOIS, A CORPORATION OF NEW JERSEY.

DRYING- PLANT.

" Specification of Letters Patent.

Application led March 2, 1912. Serial No. 681,231.

To all lwhom t may concern Be it known that I, WILLIAM J. KENNEY, acitizen of the United States,` residing at Wilmette, county of Cook,State of Illinois, have invented a certain new and useful Improvement inDrying Plants, and declare the following to vbe a full, clear, and exactdescription of the same, such as will enable shall be efficient inoperation and which will leave the material which has been dried in thebest possible condition. Where the material to be dried is in a loosecondition, as in the case of pulpy, fibrous, powdery or granularmaterial, the dryingchamber mayy form part of the apparatus containingthe furnace or heat-producing means; but it may sometimes happen thatthe drying operation must be otherwise conducted and in such cases myinvention may be regarded as comprising a simple and economical means ofproducing a large volume of heated gases.

The various features of novelty whereby my invention is characterizedwill hereinafter be pointed out with particularity in the claim; but,for a full understanding of my invention and of its object andadvantages, reference may be had to the following detailed descriptiontaken in connection with the accompanying drawings, wherein:

Figure 1 is a longitudinal vertical section through a drying plantarranged in accordance with a preferred form of my invention; Figs? 2and 3 are respectively sections on lines 2-2 and 3-3 of Fig. 1; Fig. 4is a transverse horizontal section, on

.a larger scale than Figs. 1 to 3, through the furnace; and Fig. 5 is apartly front elevation and partly a section on line 5-5 of Fig. 4.

In the drawings I have illustrated my invention as embodied in a plant4for drying the pulp remaining after the sugar has been extracted frombeets. This pulp possesses a high food value when used as a food forstock and cattle; but to put the pulp in a satisfactory commercial formit must be dried and the drying must be accomplished 1n such a manner asnot to produce burning and preferably without producing discoloration.Furthermore the drying must be accomplished in'such a manner as toprevent the pulp from being tainted and becoming unpalatable to stockland cattle. Consequently a' drying plant for beet pulp lmay be regardedas involving substantially all of the problems of care and economy whichare apt to be encountered in drying material of any kind; and'ltherefore I shall confine the detaileddescription to` this particulartype of plant althoughit will of course be understood that I do 'notdesire to be limited to any particular field or class of goods to betreated. Referring to the drawings, 1 represents furnace and 2 `asuitable receptacle or drum for containngthe material to be dried, thefurnace being adapted to furnish gases heated to the proper temperaturefor passage .through the receptacle or drum in order to effect thedrying of the drum.

3 represents a suction fan, a stack or other means for withdrawing thef'inoisture laden gases from the dryin receptacle and, in the case ofv abeet pulpp ant, for removing the light dry pulp from the drying chamber.

Jcontents of the The rate at which'the pulp dries is'dei pendent uponthe volume and the temperature of the gases passed over or through it.The temperature is limited by the necessity for keeping the gases coolenough to avoid burning the pulp and consequently the volume of theheated gases isthe only factor whichcan be changed appreciably. Conseandthe efliciency for any given capacity depends directly upon the volumeof hot gases which the furnace can deliver. Furthermore, such gasesshould be free fromf unconsu-med combustiblematerial, that is, theyshould be as nearly smokeless as possible in order to avoidcontamination or discolora- .tion of the materialwhich is being dried.

'quently the capacity of the drying plant are the combustion gases andthe volume of these is definitely defined by the amount of air requiredto sustain satisfactory combustion. The volume of gases available fordrying purposes can only be increased or decreased at the expense of aloss of eiiiciency in the furnace and with attendant smoke. Regulationof the volume of hot gases cannot successfully be obtained by drawing infree air independent of that coming through the grates to supportcombustion because an inlet for free air would disturb the draftconditions at the grate and would interfere with combustion, the ratiobetween the free lair and the air passing through the grates dependingupon the resistance encountered by the free air and that iowing throughthe grates. Even if an arrangement could be designed to produce asatisfactory proportion between the two streams of air under givenconditions, it would be impossible even approximately to maintain suchproportions since the condition of the re is always changing, the depthof the fuel constantly varying and being different over different partsof the grate.

With a good fire, the gaseous products of combustion are much hotterthan is necessary or practicable for drying purposes and therefore it isvery desirable to have some means which will make it possible to reducethe temperature of the gases to the desired degree and at the same timeutilize the excess heat for raising the temperature of air or othergases and make them available for drying purposes and it is to this endthatl my invention is directed. To attain this end I make use ofapparatus which will make'the process of combustion independent of thedraft through the drying receptacle, thus makingit possible to utilizethis draft for the purpose of drawing in free air to 'be mixed with thecombustion gases. By this means combustion and the amount of free airwhich is drawn in may be regulated independently of each other; the firebeing always efficiently maintained at such a point as may be necessaryto supply the requisite number of heat units to the drying gases, andthe amount of free air being regulated so as to produce with thecombustion gases the desired volume having the desired temperature.

In the furnace, instead of the old grates, li' prefer to place theretorts and the dead plates of the well known .Jones underfeed Stoker,the number of retorts employed depending upon the size of the furnace.In the drawings I have illustrated a single arrangement in which thereare in the furnace two troduced by means of a suitable blower 8;v

the air passing up'from this chamber through the twyer blocks 9 of theretorts as is usual in this type of stoker. Coal is'fed from hoppers 10in front of the retorts by means of the usual rams 11. As is customarywith this type of Stoker, the speed of the blower and the rate at whichthe rams are reciprocated are controlled so as always to provide therequisite feed of coal and supply of air for producing the amount ofheat desired.v The rear wall 12 of the furnace is arranged at somedistance behind the bridge wall so as to provide behind the bridge wallwhat I shall term a mixing chamber. rIhe top of the furnace is formed ofthe usual arch 13 above which is placed a roof or cover 14;`

sol

the members 13 and 14 forming between I them an air chamber 15. In thefront wall of the furnace I provide one or more openings 16 which leadfrom the outside air into the chamber above thearch. In the rear wall 12I provide a suitable conduit which communicates at its upper end withthe chamber 15 and at its lower end with the interior of the furnace. Inthe arrangement shown, the conduit is made. Ushaped as indicated at 17,one leg extending vertically through the wall near each side of the furlnace and the lowerlends` of the two legs being connected together by apassage or conduit which opens forwardly into the furnace below the topof the bridge wall as indicated at 18. The wall 12 has an opening 19therethrough for the passage of combustion gases from the furnace to thedrying receptacle.

When the plant is in operation thel fire `burns in the presence of airsupplied by the furnace blower and the gases of combustion i" are drawnback throughthe drying receptacle by the draft producing device at theoutlet endof the receptacle. At the same time air flows from the outsidethrough the opening or openings 16 in the front wall of the furnace andacross the top of the heated arch, taking up heat from the arch in itspassa e and fiowing down through the conduit 1 into the space within thefurnace just back of the bridge wall and. just below the outlet 19 forthe combustion gases. rIhe air rises and mixes with the. combustiongases as they approach and while they are passing through the outlet 19,lowering the temperature of the combustion gases and increasing theirvolume so that the quantity of `gas Howling through the dryingappakeeping down the temperature of the arch and prolonging its life.,There is consequently a saving not only of the heat 'units but also inthe furnace structure itself.

If desired, the front wall of the furnace may be provided with openings20 controlled by suitable doors or covers 21 so that '1f a greaterquantity of gas than that obtained in the manner heretofore described isdesired, some or all of the doors or covers 21 may be wholly orpartially opened, thus adl mitting additional free air into the system.This additional air which is admitted into the furnace directly over thefire hasvno disadvantageous effect on the fire because there are nounconsumed volatile matters in the combustion gases which might becooled suiiciently to form smoke, all of the volatile matters beingdriven out of the fuel in the retorts and being consumed as they riseintol 2,5 the burning mass of fuel above.

While I have illustrated and described only a single preferred form ofmy invention, and one adapted for use in connection with an old formA ofdrying receptacle, I do not desire to be limited to the specificstructural detailsthus illustrated and described, l

to the use of my invention in connection 4with any particular form ofdrying receptacle, or to .the field of Adrying beet pulp; for myVinvention is capable of many structural variationsv and is/,capable ofuse in various fields as will be evident from the definitions of vmyinvention constituting the ap- --pended claim.

I claim:

In a drying plant, a furnace having a hollow top wall, the interior ofsaid top wall communicating with atmosphere, a rear wall having anoutlet through the center thereof for the passage of the combustiongases, there being a conduit leading down through said rear wall from-the interior of the top wall and opening into the furnacebeneath saidoutlet, a bed in said furnace for supporting fuel, means for forcing theair necessary for combustion beneath said bed, a drying chamberVconnected with said furnace' and adapted to receive the combustion gasesflowing through said outlet, and means fory producing'a draft from thefurnace through said chamber.

In testimony whereof, I sign this specification in the presence of twowitnesses.

t WILLIAM J. KENNEY. Witnesses: Y

MARGARET FALAHEE, SUSAN FALAHEE.

